Clean air - the fightback: Tom Heap investigates the problems caused by air pollution, and asks how it affects children's health. He visits schools in Manchester and London and finds out about new initiatives which hope to try to reduce pollution around school sites.
Produced by Emma Campbell
Tyres have an enormous impact on the environment. What can be done to produce and dispose of them more efficiently? Tom Heap reports.
Producer: Anne-Marie Bullock
Hit the Gas!
From the cattle shed to the racetrack, ammonia is having a moment. In the wrong place it's a dangerous pollutant, in the right place it's a clean fuel for your car. Ella McSweeney and Peter Hadfield report on the two faces of the gas chemists know as NH3.
The increasing global demand for milk means more big dairy herds. More cows means more dung and urine. Mixed together they produce ammonia gas which contributes to urban air pollution and destroys sensitive habitats. In Ireland scientists have spotted big problems in peat bogs. The mosses which help create the carbon-grabbing peat are dying off in areas down-wind of dairy, pig and chicken farms. Farmers are being asked to change the way they store and spread their slurry, but it could be too late for some of the island's most vulnerable bogs.
Meanwhile, in Australia they're exploiting some interesting properties of ammonia. Environmentally-friendly hydrogen-powered cars have been around for years but they've failed to take off because hydrogen is costly and awkward to transport. By contrast, ammonia is very simple to move around from refinery to fuel station. Splitting the N from the H is straightforward, giving drivers a source of fuel that emits only water from the exhaust pipe.
So can ammonia complete its journey from environmental villain to green hero?
Producer: Alasdair Cross
The Future of Our National Parks
2019 is the 70th anniversary of the legislation that created the first National Parks in the UK. At this crucial moment for the future of our countryside, Tom Heap asks how our best-loved landscapes can work better for people and wildlife. There are now 15 National Parks – all are protected areas because of their beautiful countryside, wildlife and cultural heritage. However, much has changed since the original legislation and many of these landscapes face significant challenges, including declining wildlife, a need for housing and poor public access. Tom visits two very different parks, the Cairngorms and the South Downs, to ask communities how they think National Parks should be improved to meet the needs of the 21st century. He considers some of the key issues; such as how to balance agriculture with enhancing and connecting habitats and how to deliver rural development and housing in protected landscapes.
Producer: Sophie Anton
Heat from the Deep
The heat contained in the top 3km of the Earth’s crust could power the planet thousands of times over. Despite that, less than 1% of the world’s electricity comes from geothermal energy. That may be about to change.
Near Redruth in Cornwall a 3 mile deep hole is being dug- it will be the deepest in the UK. Cold water will be pumped down to the 200 degrees hot rocks below, the hot water returning will drive turbines to provide electricity for thousands of homes. Nearby, the Eden Project and the seawater lido in Penzance are building their own geothermal plants.
But Cornwall is just the tip of the iceberg. Geothermal electricity was first produced in 1904 at Larderello in Tuscany. Today Enel Green Power supply a third of the region's electricity from natural steam and they have plans to get much bigger, exploiting an extraordinary bit of chemistry. When water goes above 374 degrees centigrade and 221 bars of pressure it becomes a supercritical fluid. This contains five times as much energy as 200 degree water, transfers energy twice as efficiently and has a lower viscosity. Overall, you can theoretically get ten times more energy than from a similar conventional borehole.
The new technology also promises more efficient geothermal energy in regions far away from geological hot spots like Iceland and Italy. The only fly in the ointment is that some techniques involve creating bigger fractures in the rocks. Experiments at Basel in Switzerland provoked an earthquake. So can the incredible potential of new-gen geothermal be exploited without provoking protests?
Producer: Alasdair Cross